Earlylite recommended in this blog entry a particular eBay seller who specializes in these scales. I got on eBay and bought one from the same guy for what I think is a very reasonable price (about $25 including shipping). You might want to pick one up. I don't know what the highest weight is that you can put on it. But I haven't really tried to weigh anything very heavy. I weigh everything that goes into the pack separately and then sum them up so I never need to weigh the whole pack.